Double hung windows are a common type of window used in many homes and remodelings. There is a frame with a pair of tracks on each side of the frame. There is a top sash and a bottom sash. The top sash typically rides in the outer tracks, i.e. the tracks in the frame closest to the outside of a building. The lower sash rides in the inner track, i.e. that track that is closest to the interior of a house. The sash has a pair of vertical stiles that are joined to upper and lower horizontal styles. One or more panes of glass are retained in the sash. There can be an inner pane and an outer pane that extends from one vertical stile to the other and from one horizontal style to the other. There can be a third pane of glass positioned similarly with a gap between the first and second panes. The gap is usually filled with an inert gas such as argon. This structure provides a window with insulating qualities. One or more muntin bars can be present to provide a look of individual lites in the window of the type that are found in older construction.
In many double hung windows there is an issue of security. There is usually an outer screen that permits cooler air to ventilate into the house during the warmer months. In order to take advantage of the screen however, the bottom pane typically must be in a raised position. Double hung windows are usually provided with a sash lock that locks the lower and upper sash in position so that they cannot be opened from the outside. While this provides some security during the cooler months, the return of warm weather may make it difficult to use the sash lock in many instances. The sash lock has two positions, a locked position and an unlocked position. Thus the resident has a choice to either keep the window in a closed locked position or have the window sash unlocked and thus open to intruders.
In order to provide a means of ventilating a room yet provide some security, there have been a number of night latches and vent stops that have become available in the market. One such sash stop is U.S. Pat. No. 5,248,174 owned by Ashland Products. Another type of sash stop U.S. Pat. No. 4,923,230, owned by Ro Mai. These night latches or vent stops act in a similar fashion. The night latch or vent stop is placed in the face of the upper sash. Depending on the desired amount of ventilation, the night latch can be placed at any position on the face. Once the night latch is secured in the face of the window, the tumbler can be pressed in an inward and upward fashion activating a spring mechanism that will force the tumbler to an exposed position, thus creating the impeding force required to restrict movement of the lower window sash. Other prior art vent stops are U.S. Pat. Nos. 5,553,903 and 5,806,900 both of which are owned by Ashland.
As mentioned previously, the typical prior art vent stop prevented the opening of the lower sash in similar fashions. In the typical prior art the tumbler was held in a locked position via a catch portion located in the housing of the night latch. Thus, if inwardly and upwardly forces were applied perpendicularly to the face of the tumbler, these forces would release the tumbler from its locked, inactivated position, to its unlocked, activated position.
While the tumblers in the prior art night latches are capable of preventing the sliding member from moving passed a certain predetermined position, these tumblers have an unfavorable characteristic. That is in the prior art vent stop, in order for the user to free the tumbler from its inactivated position to its activated position or vice versa. the user must apply a multitude of forces in a variety of different angles.
Although the night latch and/or vent stops are capable of preventing the lower sash from moving passed a certain desired position, their utility is unfortunately outweighed by their inherent clumsy composition. The night latch in the present invention improves on the prior art shortcomings by implementing a unique method of activating and inactivating the tumbler from the housing, without taking away from its utility and its aesthetic quality.